Bilateral Vestibulopathy: Vestibular Function, Dynamic Visual Acuity and Functional Impact

Abstract

Introduction: Patients suffering from bilateral vestibular hypofunction (BVH) often experience ataxia as well as visual instability. Even though progress has been made in vestibular testing, insights regarding vestibular deficit in BVH remain incomplete since no method allows evaluation of frequency ranges of vestibular sensors in a continuous way. The aim of our study was to give a detailed description of the level of vestibular deficit in different ranges of vestibular stimulation and an exhaustive evaluation of the functional impact including dynamic visual acuity (DVA) in a cohort of BVH patients in different etiologies.Methods: We prospectively included 20 patients with chronic BVH. All patients underwent clinical evaluation and functional assessment including evaluation of their symptoms related to BVH, quality of life questionnaire and DVA in the horizontal and vertical plane. Patients underwent vestibulo-ocular reflex (VOR) testing using rotatory chair, caloric stimulation and video head impulse (vHIT) in the plane of the 6 canals, and cervical and ocular Vestibular evoked myogenic potentials.Results: Mean rotatory VOR gain was 0.07 (SD = 0.07). Mean rotatory VOR gain during vHIT for the lateral, anterior and posterior canals was respectively < 0.28, < 0.34, and < 0.20. Mean loss of DVA in the 4 directions was >0.30 LogMAR. In our population fall frequency was significantly higher in patients with lower UniPedal Stance Test (UPST), higher Dizziness Handicap Inventory and Ataxia Numeric Scale (ANS) scores, as well as greater loss of upwards DVA. Patients with ototoxic BVH had a significantly higher residual VOR gain during vHIT in the anterior canal plane and lower DHI than other patients. In the general population anterior canal function was significantly higher than lateral or posterior canal function.Conclusions: This study gives extensive descriptive results of residual vestibular function, DVA and quality of life in a population of patients suffering from severe BVH. UPST and ANS are good indicators for fall risk in case of BVH. Gentamicin induced BVH seems to have a lesser impact on quality of life than other etiologies.Anterior semi-circular canal function seems less deteriorated than lateral and posterior function.

Prospective cohort study on the predictors of fall risk in 119 patients with bilateral vestibulopathy

“…The observed fall prevalence in this study is comparable with previous studies evaluating falls in BV patients. Schniepp and colleagues reported falls in 21 out of 55 (39%) BV patients in the preceding six months [26], Hermann and colleagues reported falls in 11 out of 20 (55%) BV patients since the onset of BV [27]. Results will now be discussed in accordance with the four a priori hypotheses.…”

“…Significantly higher DHI scores, lower unipedal stance test, higher ataxia numeric scales and greater loss of upwards Dynamic Visual Acuity were observed in the patients with falls. Age was again not different between fallers and non-fallers [27]. On the contrary, Herdmann et al found a younger age to be a risk factor for falling [31].…”

“…The DHI have repeatedly been demonstrated to be a good predictor for falls, based on our population a cut-off of > 47 would be proposed. Also the Oscillopsia severity questionnaire (OSQ) (score > 27.5) and a unipedal stance test of less than 4 seconds [27] seem indicative for identifying BV patients at risk for falling and can be easily performed at consultation. On the other hand, residual vestibular function, age, hearing, underlying BV etiology and disease duration are not predictive for falls.…”

Update on Cerebellar Ataxia with Neuropathy and Bilateral Vestibular Areflexia Syndrome (CANVAS)

“…Video HIT is the only tool that can also be used for the evaluation of vertical semi-circular canals [41]. Nevertheless, a disease-specific sparing of the anterior semi-circular canals has been highlighted in BVP rendering gain of the vertical canals a less reliable criterion [42,43].…”

Bilateral vestibular hypofunction: a literature review and a case report

“…U ponad połowy chorych początkowe objawy mają lekki charakter. Z upływem czasu zwiększają się, prowadząc do znacznego pogorszenia komfortu życia [17][18][19]. Pogłębia się lęk przed zawrotami głowy, dlatego chorzy rezygnują z aktywności fizycznej, nierzadko izolując się od społeczeństwa i zamykając w domach.…”